The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1998
Filed:
Dec. 20, 1996
Akira Ishii, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A method and apparatus for object profiling is disclosed wherein a laser beam generated by a laser diode 102 is directed to the object surface 101, the apparatus scans the surface 101 and receives the illuminated point image by a charge storage type one-dimensional array of light receiving elements 107; the array 107 is scanned every predetermined period so as to sense a position of the illuminated point image; the object surface coordinates are then obtained by the principle of triangulation, and thereby profile of the object surface 101 can be measured. The laser beam generated by laser diode 102 is intermittent such that the beam is turned on/off at intervals of a predetermined time, preferably ranging from 10 ns to 100 ns. The received signal during unilluminated (turned-off) period delays one period via the FIFO 119-3, while that during the illuminated (turned-on) period is supplied to the subtraction unit 119-6 without delay. The subtraction unit 119-6 subtracts the signal of the unilluminated period from that of the illuminated period. The external interference light due to arc light of a welding torch, etc., ordinarily having a fluctuation frequency of much lower than 100 kHz, irradiates the array 107 at an almost equal intensity in both of the illuminated and unilluminated periods, so that the interference components can be eliminated by subtraction.